🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2004 Chassis Code: GDB Engine Code: EJ257 Generation Generation Designation: Second Generation (GDB) Generation Years: 2002-2007 Codes Vin Drivetrain Code: H (for AWD) 👋 Introduction Market Position Performance Segment: Compact Performance Sedan/Wagon Rally Heritage: Directly influenced by Subaru's World Rally Championship (WRC) success Competitive Analysis Key Competitors: Mitsubishi Lancer Evolution, Ford Focus RS, Volkswagen Golf R Key Features Drivetrain Philosophy: Symmetrical All-Wheel Drive (AWD) system with Driver Controlled Center Differential (DCCD) Engine Philosophy: Performance-tuned turbocharged Boxer engine Suspension Tuning: Performance-oriented suspension setup for enhanced handling Braking System: Upgraded Brembo braking system for superior stopping power 📋 Manual Details Coverage Areas Coverage Scope: Complete vehicle service and repair Engine Coverage: All engines (specifically EJ257 for WRX STI) Drivetrain Coverage: All-Wheel Drive (AWD) system, differentials, transmission Body Coverage: Exterior panels, interior trim, chassis components Electrical Coverage: Wiring diagrams, component testing, ECU diagnostics Page Count Estimated Page Count: 1500+ Manual Type Manual Type: Official Service and Repair Manual Language Language: English Format Format: PDF File Type: Digital (Searchable PDF) 📖 Manual Coverage Systems Covered Engine Mechanical: Engine teardown, assembly, cylinder head, pistons, crankshaft, lubrication, cooling Engine Management: Fuel injection, ignition system, emissions control, ECU diagnostics, sensors Transmission: 6-speed manual transmission (TY756VW4CA), clutch system, driveline components Suspension: Front struts, rear multi-link, springs, shocks, anti-roll bars, alignment procedures Brakes: Front Brembo 4-piston calipers, rear 2-piston calipers, ABS system, brake fluid Steering: Power assisted rack and pinion, steering column Electrical System: Starting and charging system, lighting, instrumentation, audio system, power windows, airbags HVAC: Air conditioning, heating, ventilation, refrigerant handling Body And Chassis: Frame, body panels, doors, hood, trunk, glass, interior trim Procedures Included Preventative Maintenance: Oil changes, filter replacements, fluid checks, spark plug replacement, belt inspection Troubleshooting: Diagnostic flowcharts for common and uncommon issues, symptom-based troubleshooting Repair And Rebuild: Detailed step-by-step instructions for component removal, disassembly, repair, and reassembly Diagnostics: OBD-II diagnostics, sensor testing, actuator testing, ECU relearning procedures Specifications And Tolerances: Torque specifications, measurement tolerances, clearances Wiring Diagrams: Comprehensive electrical schematics for all vehicle systems Technical Depth Depth Level: Comprehensive (from basic maintenance to full engine/transmission rebuilds) Diagnostic Capability: Advanced diagnostic procedures, component-level testing Wiring Detail: Pinouts, wire colors, connector diagrams 📊 Manual Specifications File Format File Format Type: PDF (Portable Document Format) Searchability: Text-searchable, allowing quick access to specific information Printability: Printable pages for workshop use Digital Features: Hyperlinked sections for easy navigation (typical for professional PDFs) Print Quality Image Resolution: High-resolution images and diagrams for clarity Binding Type Binding Type: N/A (Digital PDF) Paper Type Paper Type: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally-opposed turbocharged Boxer 4-cylinder Displacement: 2.0 Liters (1994 cc) Bore X Stroke: 92.0 mm x 75.0 mm Compression Ratio: 8.4:1 Valve Train: DOHC, 16 valves (4 valves per cylinder) Performance Horsepower: 300 hp @ 6000 rpm (SAE Net) Torque: 290 lb-ft @ 4000 rpm (SAE Net) Fuel System Fuel Delivery: Sequential multi-port fuel injection (MPI) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Turbocharger: IHI VF30 (or similar, depending on market) Intercooler: Top-mounted air-to-air intercooler 🔧 Transmission Standard Transmission Type: 6-speed manual Transmission Model: TY756VW4CA Optional Optional Transmission: N/A (6-speed manual was standard on WRX STI) Features Dccd: Driver Controlled Center Differential (DCCD) with automatic and manual modes Differential Type: Front: Helical LSD; Rear: Active Torque Split DCCD with Viscous LSD 📐 Dimensions Exterior Length: 4415 mm (173.8 inches) Width: 1770 mm (69.7 inches) Height: 1440 mm (56.7 inches) Wheelbase: 2625 mm (103.3 inches) Front Track: 1515 mm (59.6 inches) Rear Track: 1505 mm (59.3 inches) Weights Curb Weight: Approx. 1460 kg (3219 lbs) Gross Vehicle Weight Rating: Approx. 1900 kg (4189 lbs) Cargo Trunk Volume: Approx. 0.33 m³ (11.8 cu ft) (Sedan) 🛡️ Safety Features Ratings NHTSA Front Crash Test: 4/5 Stars (Driver/Passenger) NHTSA Side Impact Test: 4/5 Stars (Front/Rear Passenger) IIHS Moderate Overlap Front: Good Active Features ABS: 4-wheel Anti-lock Braking System (ABS) E Brake Force Distribution: Electronic Brake-force Distribution (EBD) Traction Control: Standard Traction Control System (TCS) Passive Features Airbags: Front driver and passenger airbags, front side-impact airbags Seatbelts: 3-point seatbelts with pretensioners and load limiters Child Seat Anchors: LATCH (Lower Anchors and Tethers for CHildren) system 💡 Technology Features Infotainment Head Unit: Factory-installed CD player with AM/FM radio. Higher trims may have premium audio systems. Speaker System: Standard 4-speaker or optional 6-speaker audio system (e.g., Clarion). Driver Assistance Cruise Control: Standard electronic cruise control Anti Theft System: Factory immobilizer and alarm system Connectivity Auxiliary Input: Optional or aftermarket auxiliary input for audio devices 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 6 months (severe conditions), or 7,500 miles or 12 months (normal conditions) Air Filter Replacement Interval: Every 15,000-30,000 miles, or as needed based on inspection Cabin Air Filter Replacement Interval: Every 15,000-30,000 miles, or annually...